#include<iostream>
#include<bits/stdc++.h>
using namespace std;
int main()
{
    freopen("duel1.in","r",stdin);
    freopen("duel1.out","w",stdout);
    long long a,b[100];cin>>a;long long l=0;
    for(int i=1;i<=a;i++)
    {
        cin>>b[i];
    }
    for(int i=1;i<=a;i++)
    {

        for(int j=1;j<=i;j++)if(b[i]>b[j])swap(b[i],b[i-1]);
    }
    for(int i=1;i<=a;i++)
    {
        if(b[i+1]!=b[i])
        {
            l++;i++;
        }
    }
    cout<<a-l;
    fclose(stdin);
    fclose(stdout);
    return 0;
}
